Flow Transmitters

Clark Solutions—a leading manufacturer and distributor of pumps, valves, and flow instrumentation introduces its CSLFB Ultrasonic Flow Transmitters.  These transmitters are ideal for measuring flow rates of acoustically conductive liquids, including most clean liquids and many liquids with entrained solids.  Model CSLFB Ultrasonic Flow Transmitters are designed for full-scale flow ranges from 15 to 400 GPM in ¾” to 3” pipe. They are a rugged cast brass design and have an accuracy of ±0.75% F.S. At the heart of the Clark Ultrasonic Flow Transmitter is a proprietary mixed signal ASIC, (Application Specific IC,) which allows sophisticated timing, control and transducer drive circuitry to be combined on a single integrated circuit. The ASIC uses a special algorithm that is an improvement upon the standard single-path measurement technique. ClarkSonic transmitters utilize the “sing around” method, where the ultrasonic transducer alternates between transmitting and receiving to measure differences in flight time between upstream and downstream transmissions. The flight time of the sound pulse from the transmitting transducer to the receiving transducer will be shortened if the pulse is launched in the direction of flow, and increased if launched opposite to the direction of flow. By alternating the transmitting and receiving transducers, the difference in these transit times can be used to calculate the velocity of the flow, which when multiplied by the area of the pipe results in a measure of volumetric flow rate. The primary advantage of the Sing Around method is that the velocity of the fluid is being measured independent of the relative speed of sound in that given fluid. The output of Clark transmitters is also unaffected by changes in fluid temperature, density and viscosity.